Control system

ABSTRACT

Fluidic control apparatus including structure defining a control passage for the flow of fluid along a straight path, the control passage being open at least one end, a slot dividing the control passage into two sections so that two opposed intermediate ports are defined in the walls of the slot, inlet means for supplying fluid to one of the sections, and outlet means for receiving fluid flow from the other section at an intermediate point along the length of the other section. A first blocking member is mounted for movement adjacent the open end of the passage to block flow through that end and a second blocking member is mounted for movement into the slot to interrupt fluid flow from the first section of the passage to the second section of the control passage.

Jan. 18, 1972 3,516,439 6/1970 Hickseta1........................137/31.5X

[ CONTROL SYSTEM ,480,03l Cushing...................................137/82 Inventor: Leon A. Gllckman, Westwood, Mass.

[73] Assignee: Keystone Bay State Industries, llnc., Primary ExaminerSamuel Scott Boston, Mass. Att0meyWillis M. Ertman ABSTRACT [22] Filed: Nov. 4, 1969 [21] Appl.No.: 873,801

Fluidic control apparatus including structure defining a control passage for the flow of fluid along a straight path, the con- [52] U.S.Cl.........................,....................137/608,137/815 trol passage being open at least one end, a slot dividing the control passage into two sections so that two opposed inter mediate ports are defined in the walls of the slot, inlet means [51] 1nt.C1. [58] Field 011 Search................

for supplying fluid to one of the sections, and outlet means for References Cited receiving fluid flow from the other section at an intermediate UNITED STATES PATENTS point along the length of the other section. A first blocking member is mounted for movement adjacent the open end of the passage to block flow through that end and a second 137/81 5 137/315 blocking member is mounted for movement into the slot to interrupt fluid flow from the first section of the passage to the second section of the control passage. 137/81 5 Johnsonm.............................137/815 12 Claims, 5 Drawing Figures 023 015 Meier 271 Katz......... 161 Rexford 1/1970 Lilly......... 094 3/1970 SUMMARY OF INVENTION This invention relates to control apparatus and more particularly to fluidic control apparatus and to systems incorporating such control apparatus.

It is an object of this invention to provide novel and improved condition sensing systems that employ a fluidic device for transmission of information concerning the sensed condition to a remote point. An example is a gauging system in which work pieces having a dimension above or below a predetermined range should be identified either for control or informational purposes, for example. In another such system it is desired to transmit information concerning a cyclically occurring condition.

It is another object of this invention to provide novel and improved control apparatus of the fluidic type which has two stable states.

Another object of the invention is to provide novel and improved fluidic control apparatus which operates in response to low-pressure input and is simple, compact and reliable.

A further object of the invention is to provide novel and improved control systems that incorporate a bistable fluidic control device.

In accordance with the invention there is provided fluidic control apparatus which includes structure that defines a control passage for the flow of fluid along a straight path, the control passage being open at at least one end. The control passage is divided into two sections by a slot or gap so that two opposed intermediate ports are defined in the walls of the slot. Inlet means is provided for supplying fluid to one of the sections and outlet means is provided for receiving fluid flow from the other section at an intermediate point along the length of the section. In one stable state of the apparatus, fluid flow applied to the inlet means will not create fluid flow in the outlet means. when flow at a port at an outer end of the passage is blocked, however, by closing the port or positioning a blocking member across the port to substantially block flow through that port for example, fluid flow is established in the outlet means. Fluid flow from the inlet means through the passage to the outlet means continues after the end port is unblocked so that the device is in a second stable state. The device may be switched from the second stable state to the first stable state merely be interposing a blocking member in the slot to interrupt the flow from the first section to the second section of the control passage. Such interruption terminates fluid flow in the outlet means and fluid flow in the outlet means is not resumed upon removal of the blocking member from the slot but only after that member has been removed from the slot and an end port is again blocked.

In a preferred embodiment the inlet and outlet means are disposed at right angles to the control passage and each intersects the control passage at an intermediate point in its section. The inlet and outlet means are passages of the same dimension as the control passage (0.040 inch). The slot between the two sections of the control passage may have a widthof l 2M0 2 times the dimension of the control passage (e.g., 0.060-0080 inch in that particular embodiment) and a depth beyond the control passage of at least twice that dimension (e.g., 0.080 inch). This fluidic control unit operates reliably at inlet pressures of l to 3 inches of water and is suitable for controlling larger systems through use of interface valves or similar devices.

Other objects, features and advantages will be seen as the following description of particular embodiments progresses, in conjunction with the drawings, in which:

FIG. 1 is a perspective view of a dial indicator control system constructed in accordance with the invention;

FIG. 2 is an enlarged perspective view of portions of the dial control system shown in FIG. 1;

FIG. 3 is a sectional view of the fluidic switch component incorporated in the dial control system shown in FIGS. 1 and 2;

FIG. 4 is a diagrammatic side view of timer apparatus incorporating the fluidic switch component shown in FIG. 3; and

FIG. 5 is an end view of the apparatus shown in FIG. 4.

DESCRIPTION OF PARTICULAR EMBODIMENT With reference to FIG. ll there is shown a dial gauge 10 which includes a case 12 in which a movement is mounted for rotating vanes 14, 16 in response to :movement of spindle 18. A faceplate 20 on the case 12 carries markings 22 which may be calibrated as a function of movement of spindle 18. A transparent cover plate 24 is mounted on ring 26 which is in turn mounted on case 12 for rotation relative to that case and locked in angular position by clamp 2-8 and lock screw 30.

Carried by member 26 is a fluidic switch structure 32 which has an inlet line 34 and an outlet line 36. As indicated in FIG. 2 the inlet 34 may be connected to a suitable source of pressure 38 (a typical pressure applied to an inlet line 34 being 3 inches of water (0.1 p.s.i.) and the outlet line 36 is connected to an interface valve 40 which controls the second system such as a higher pressure fluid system having lines 42 and 44.

With reference to FIG. 3, the fluidlic switch component includes a block 50 of plastic or other suitable material that has a transverse central passage composed of two aligned sections 52 and 54 that are separated by a gap defined by slot 56 that has two opposed walls 58, 60. The transverse passage may extend entirely through the block 50 or one end of passage may be closed off as at 62 so that only one outside port 64 is provided at one end of the passage. Intermediate ports 66, 68 are provided in walls 58 and 60, respectively, of slot 56. An inlet passage 70 intersects section 52 of the transverse passage at a right angle and an outlet passage 72 intersects section 54 of the transverse passage, also at a right angle. Coupling tubes 34, 36 (of larger diameter than passages 70 and 72) are connected to those passages.

In a particular embodiment sections 52, 54, 70 and 72 are of 0.040 inch diameter. The length (A) of each transverse passage section from the right angle junction to its intermediate port should be in the range of 2 to 2% times the diameter of the transverse passage while the length (L) of outlet passage 72 should be in the range of 6 to 7 times this diameter. In this embodiment vane .16 need only have that thickness necessary to give it sufiicient stiffness and may be as thin as 0.002 inch, the width of slot 56 is in the range of 0.060 to 0.080 inch, and the slot has a depth (D) of at least 4 times the diameter of the transverse passage.

The fluidic switch component is mounted on the rotatable ring 26 and locked in a position relative to dial 20 by clamp 28. The switch 32 thus has its outlet port 64 positioned so that vane 14 may pass close by (within 0.002-0.015 inch) to modify the flow of air through that port, and vane 16 may pass through slot 56 to block flow of air from transverse passage 52 to passage section 54. The angular offset of vane 16 with respect to vane 14 is adjustable.

In operation of this device with air pressure applied to inlet line 34, there will be no significant flow of air through outlet passage 36 until port 64 is blocked. After port 64 is blocked, flow of air from passage 34 through passage 70, section 52, section 54 will be directed into passage 72 and to outlet passage 36. This flow of air to outlet passage 36 will continue after the blocking vane is removed from the vicinity of port 64 but will be interrupted by the interposition of a vane in slot 56. Thus this fluidic switch has two stable states and is switched from one stable state to the other by the temporary presence of the blocking member adjacent a port of the transverse passage. (If the port 62 should be open, flow in passage 72 can be established solely by blocking port 62.)

A second embodiment is shown in FIGS. 4 and 5. A fluidic switch unit 32' is mounted on a framework which supports a timing mechanism that drives output shaft 82. On shaft 82 are mounted two timing members 84., 86. Disc 84 is aligned with switch structure 32 so that it passes in a plane adjacent (within 0.002-0.015 inch) of port 64", and vane 86 is aligned so that it passes through slot 56'. As shown in FIG. 5, disc 84 has a cutout 88 along its periphery 90, respectively. As the two members are rotated by drive 80 in the clockwise direction as indicated in FIG. 5, there is no airflow as long as disc 84 has its peripheral portion positioned in slot 56'. The switch is released during the angular rotation of vane 84 from points 92 to 94. Vane 86 is rotatable relative to disc 84 and in the position shown in FIG. 5, will trigger the switch to airflow condition at angular position 96 and the switch will remain in airflow condition until terminated when the disc 84 reaches angular position 94. Thus this device provides a timing mechanism which cyclically provides airflow through outlet line 36 for an interval determined by the relative position of members 84 and 86. This device provides a simple switch mechanism that does not require electricity, the motor 80 for example being a spring motor that is rewound periodically using a portion of the air from outlet line 36', for example.

While particular embodiments of the invention have been shown and described, various modifications thereof will be apparent to those skilled in the art and therefore it is not intended that the invention be limited to the disclosed embodiment or to details thereof and departures may be made therefrom within the spirit and scope of the invention as defined in the claims.

What is claimed is:

l. Fluidic control apparatus comprising structure defining a control passage for the flow of fluid along a straight path, said control passage being open at at least one end, a slot dividing said control passage into two sections so that two opposed intermediate ports are defined in the walls of said slot, inlet means for supplying fluid to one of the sections, outlet means for receiving fluid flow from the other section at an intermediate point along the length of said other section, a first blocking member mounted for movement adjacent said open end of said passage to block flow through that end and a second blocking member mounted for movement into said slot to interrupt fluid flow from the first section of the passage to the second section of said control passage.

2. The apparatus as claimed in claim 1 wherein the slot between said two sections of said control passage has a width of 1% to 2 times the cross-sectional dimension of said control passage and a depth beyond said control passage of at least twice that cross-sectional dimension.

3. The apparatus as claimed in claim 1 wherein said inlet and outlet means are passages disposed at right angles to said control passage.

4. The apparatus as claimed in claim 3 wherein said inlet and outlet passages have the same dimension as said control passage.

5. A control system comprising first and second members mounted for movement to first and second points offset from one another along predetermined paths and a fluidic control unit having structure defining a first end wall disposed adjacent said first point and a slot portion in which said second point is disposed, a control passage having two sections, one on either side of said slot, and arranged so that said control passage defines two opposed intermediate ports in the walls of said slot and an end port at said end surface, inlet means for supplying fluid to one of said control passage sections, and outlet means for receiving fluid flow from the other control passage section at an intermediate point along the length of said other section, such that movement of said first member to said first point modifies the fluid flow through said control passage to initiate fluid flow into said outlet means, which fluid flow continues after removal of said first member from said first point, and movement of said second member to said second point interrupts fluid flow to the outlet means and such fluid flow remains interrupted after removal of said second member from said first point.

6. The system as claimed in claim 5 and further including means for continuously supplying fluid to said inlet means.

7. The system as claimed in claim 5 wherein said'first and second members are vanes mounted for movement in planes offset from one another.

8. The system as claimed in claim 5 wherein said inlet and outlet means are passages disposed at right angles to said control passage.

9. The system as claimed in claim 8 wherein said inlet and outlet passages have the same dimension as said control passage.

10. The system as claimed in claim 9 wherein the slot between said two sections of said control passage has width of 1% to 2 times the cross-sectional dimension of said control passage and a depth beyond said control passage of at least twice that cross-sectional dimension.

11. The system as claimed in claim 10 wherein said first and second members are vanes mounted for movement in planes offset from one another.

12. The system as claimed in claim 11 and further including means for continuously supplying fluid to said inlet means at a pressure in the order of several inches of water.

t k l 

1. Fluidic control apparatus comprising structure defining a control passage for the flow of fluid along a straight path, said control passage being open at at least one end, a slot dividing said control passage into two sections so that two opposed intermediate ports are defined in the walls of said slot, inlet means for supplying fluid to one of the sections, outlet means for receiving fluid flow from the other section at an intermediate point along the length of said other section, a first blocking member mounted for movement adjacent said open end of said passage to block flow through that end and a second blocking member mounted for movement into said slot to interrupt fluid flow from the first section of the passage to the seCond section of said control passage.
 2. The apparatus as claimed in claim 1 wherein the slot between said two sections of said control passage has a width of 1 1/2 to 2 times the cross-sectional dimension of said control passage and a depth beyond said control passage of at least twice that cross-sectional dimension.
 3. The apparatus as claimed in claim 1 wherein said inlet and outlet means are passages disposed at right angles to said control passage.
 4. The apparatus as claimed in claim 3 wherein said inlet and outlet passages have the same dimension as said control passage.
 5. A control system comprising first and second members mounted for movement to first and second points offset from one another along predetermined paths and a fluidic control unit having structure defining a first end wall disposed adjacent said first point and a slot portion in which said second point is disposed, a control passage having two sections, one on either side of said slot, and arranged so that said control passage defines two opposed intermediate ports in the walls of said slot and an end port at said end surface, inlet means for supplying fluid to one of said control passage sections, and outlet means for receiving fluid flow from the other control passage section at an intermediate point along the length of said other section, such that movement of said first member to said first point modifies the fluid flow through said control passage to initiate fluid flow into said outlet means, which fluid flow continues after removal of said first member from said first point, and movement of said second member to said second point interrupts fluid flow to the outlet means and such fluid flow remains interrupted after removal of said second member from said first point.
 6. The system as claimed in claim 5 and further including means for continuously supplying fluid to said inlet means.
 7. The system as claimed in claim 5 wherein said first and second members are vanes mounted for movement in planes offset from one another.
 8. The system as claimed in claim 5 wherein said inlet and outlet means are passages disposed at right angles to said control passage.
 9. The system as claimed in claim 8 wherein said inlet and outlet passages have the same dimension as said control passage.
 10. The system as claimed in claim 9 wherein the slot between said two sections of said control passage has width of 1 1/2 to 2 times the cross-sectional dimension of said control passage and a depth beyond said control passage of at least twice that cross-sectional dimension.
 11. The system as claimed in claim 10 wherein said first and second members are vanes mounted for movement in planes offset from one another.
 12. The system as claimed in claim 11 and further including means for continuously supplying fluid to said inlet means at a pressure in the order of several inches of water. 